Ellen Page may have surprised those in the audience at the Human Rights Campaign's Time to THRIVE conference on Friday when she came out as gay, but for Page, the decision was well thought-out.

"It was her idea," Michael Cole-Schwartz, director of communications for HRC tells PEOPLE. "She came to Time to THRIVE to do it in a place where youth-serving professionals were gathered, and a place where she could have the most direct and profound impact on LGBT young people."

Mikki Cichocki, an educator who was among the 650 youth professionals in attendance, recalls the atmosphere in the room when Page made the announcement during her 8-minute speech.

"It was exhilarating," she said. "You didn't know this was going to happen. You could see her sense of relief, like, 'I got it out. I said it out loud.' "

Those gathered immediately responded with great warmth.

"There was this collective wave of emotion just supporting her, and a roar when she did actually say the words," says Cichocki. "You knew you just saw something that was momentous."